Update on 8/18/2026: yql0991666 have cheated to become a Master. How can he still not be banned?
Update: Congratulations to yql0991666, the CHEATER is disabled! Good job, Mike!
I, BitByBit123, suspect that yql0991666 is a cheater. I would like to report some suspicious behaviors and request an investigation.
Update on 8/18/2026
yql0991666, could you explain 387437964 387437988 how can you write 1.6KB code in 3 seconds?
Looking at the code for Problem E, what kind of person would write such a long definition on a single line (the fourth line)?
If you interpret this as a way to make the code more compact (by consolidating lines), then why are the assignment statements on lines 19 through 24 separated?
The only explanation is that the AI-generated code was partially modified.
Also yql0991666 you didn't solve problem D because you allocated an array smaller than required, Even when there's a notification saying the data range changed. The only explanation is that yql0991666 can't read English and copied the wrong statement to ChatGPT.
And yql0991666 you use indention with a tab size 4 before but 8 now, WHY??
Also lets check out his weird code.
Suspicious contest behavior
As shown above, yql0991666 solved multiple problems in an unusually short period of time and in an unusual order. Some other examples:
https://codeforces.me/contest/2252/submission/385960817
https://codeforces.me/contest/2252/submission/385961550
During contests, the user submitted multiple accepted solutions for the same problem, where the only visible changes were formatting-related (such as spaces or indentation).
AI-like code style and inconsistent coding habits
Examples:
https://codeforces.me/contest/2253/submission/386124818
https://codeforces.me/contest/2248/submission/385185432
https://codeforces.me/contest/2252/submission/385961550
Some submissions contain coding patterns that are commonly seen in AI-generated code, for example:
if(cin>>T)
{
while(T--)
{
/* ... */
}
}
and:
if(!(cin>>n))return 0;
These patterns appear in some of the user's submissions but not in others, indicating a significant inconsistency in coding style.
Additional inconsistencies include:
- Mixing
int*andint[]styles in function parameters. - Mixing spaces and tabs for indentation.
Examples:
https://codeforces.me/contest/2253/submission/386124818
https://codeforces.me/contest/2253/submission/386109857
https://codeforces.me/contest/2253/submission/386124802
I understand that coding style alone cannot prove cheating, but these changes may indicate that some submissions were not written in the user's usual style.
Inconsistent performance
yql0991666 previously had performances around the 10000+ rank range, but recently achieved several extremely high placements, including top 50 finishes, with a rapid rating increase.
Relevant information:
The improvement appears to be significantly inconsistent with the user's previous competitive programming history.
Additionally, according to publicly available records, yql0991666 scored 100 points in CSP-J2024 and 130 points in CSP-J2025. These results suggest that he can hardly solve problems with difficulty higher than *800 or *1000, which appears inconsistent with the user's recent Codeforces performance.
Source:
Additional information
I personally know this user, Yin Qilong, from the Chinese OI community. There have been previous controversies involving this user, including alleged cheating and harassment on other platforms such as Luogu.
I understand that these points alone may not conclusively prove cheating, so I would appreciate it if Codeforces staff could review the account and related submissions.
(By the way, it has been a long time since the last rollback and there're a lot of cheaters in the latest contests, so could we have a rollback?)
I have heard a bit about yql0991666. In my opinion, he does not have the strength to get such results in the contest, and his submission patterns are highly questionable. I consider him a cheater.
Don't you see cheaters are mostly in China? I'll give you a look how many cheaters are on Luogu.
QbdQ
FLplc123
PolyHu
Zyf_c
tangyuxianxiansen2
huletian11
Muted_Gloves
Cmf9812
cpgz666
brocluo
Cx1025
skys1982
Binary_Dreamer
mys2013
tendness_love
future_robot
UU_cmyk
qs20250339
whdym
I_AK_WC
shen781022
......
(AT LEAST TWENTY times more cheaters)
And that's only two days worth of cheaters. Think about that!!!
The reason why so many cheaters can be caught on Luogu is that Luogu has a great anti-cheating system. Think about that!
Even worse, Luogu says that it has recently been using AI to catch cheaters, which is 99.9% correct. it means that Luogu can catch more cheaters more effectively and more accurate.
Many stupid primary students use AI in China.
I mean they ain’t take this serious if they are primary schooler.
The website of Luogu is: luogu.com.cn
Yes, but i'm afraid they can't open luogu.com.cn, so i typed luogu.com instead, which is it's international website (e.g. leetcode.com)(which i'm afraid that i can't open).
fuc you
Please spell correctly
fu yu' mo
He's cheater and he become a master
Translation to English be like:
你需要把 把牙齿 翻译为 ax_by_c
That guy with the teeth is ax_by_c.
It's laughable to see someone calling Sponge Bob "that guy with the teeth"( ＾皿＾)っ( ＾皿＾)っ( ＾皿＾)っ
Actually, ”that guy with the teeth” refers to ax_by_c instead of SpongeBob.
MikeMirzayanov Vladosiya
The person has two Luogu accounts: the first one (yql0991666) was banned, and the second one (__yql0991888__) was a cheater and received a brown tag
Update:His second Luogu account has been banned
“Additionally, according to publicly available records, yql0991666 scored 100 points in CSP-J2024 and 130 points in CSP-J2025. These results suggest that he can hardly solve problems with difficulty higher than *800 or *1000, which appears inconsistent with the user's recent Codeforces performance.”
I also don't think his level in domestic competitions(i.e., CSP-J) can reach the standard of solving three problems in a Codeforces Div. 1 round.
*ps. CSP-J has 4 problems with rating *800~1200, *800~1200, *1300~1400 and *1500~1700. I'm not sure if he's capable of solving an 800-level problem on Codeforces.
Ban that cheater pls. I don't wanna see crazy cheaters like that anymore.
Don't downvote me please. wo shi chuan zi.
Sorry.
Then stop send trash message like this,please.It's meaningless.
More and more cheaters who should be punished. When rollback?
No ma I le, I shi yin qi dragon.
hyw
?
chuan again da die(
rk++
I strongly support banning yql0991666.
There is ample evidence to support this report, and I don’t believe all of the above is just a coincidence.
Supplement:
What's more, he even used both tabs and spaces for indentation in a single block of code (even in a single line)! This is highly unlikely to happen if he wrote the code manually in an editor. I believe he modified this AI-generated code.
Evidence:
Note: a little round dot represents a space while a arrow represents a tab in the picture(in the view of Microsoft VS Code).
cause dragon is so strong !!1
There are more and more cheaters in div2, and even div1.
His Luogu(Chinese OJ) accounts:
Account1(Banned)
Account2(has been flagged as a cheater)
"Honestly, a rollback isn't enough at this point. We need a new 'Skip to Ban' button for accounts with a rating graph that looks like a SpaceX rocket launch.
Excellent investigation, BitByBit123!"
SpaceX rocket launch lmfao
This you dou can know.I bx you.
I used to think, that no one will cheat in div 1. because only legitimate people can get there bcz of hardness of questions. but I was wrong. cheaters even cheating in div 1.
The Codeforces Div-2 lobby is so bad that even after solving A, B, C, people end at 1200 rating due to such cheaters, there are so many like him
Oh yet another cheater. And I bet there's a lot more. What the hell is the point? I don't get why they ever wanna cheat.
They just want that sweet purple color to flex without suffering through 'WA on test 2'. Pure fake ego.
If we dont stop him he will soon get to red. Just check out his performance.
I'm stronger than yql.
Tell us something we don't know.
Yql is stronger than me.
Tell us something we know.
wzy is stronger than me.
ppppp。！
I don't think he has the ability to debug AI and become a IGM:)
he even changed the AI's coding style to hide that he was cheating
he was showing off on WeChat Moments that he solved three problems :D
Bro spent more effort hiding the AI code than it takes to actually solve Div 2 A.
English big hand! I /bx.
Say dian something big home don't know, I am is Cause Dragon. I am is a gay. Big god no kill me, no kill me, I have no money.
If you keep such speaking way, I will teach you how to speak English with my big red sausage.
收到！！！
yqlgod yqlgod, no kill me no kill me.
Stop downvote QAQ
My Contribution is -8 now!
Oh,bro.you English are very bad,I think I need to immediately go to your computer room and educate you on English.Like zak all kill IOI.
666 怎么都给我 downvote，是不是都嘲讽我英语不好？那我就直说了，我语文也不好。
Oh,You are clever,old X,let me look!
不要！
They spoke English but I think only Chinese people can understand what they were talking about, because it is "Chinglish".
Chinese people feel hard to understand too. :)
Even if you use AI to translate it, you still won't know what weird things they are talking about, because China's internet environment has produced some weird things that only Chinese people know.
I've lived in China my whole life. I still only understand like half of it. Ahem. (And yes a bunch of what they're talking abt is just uh things that are best left in Chinglish, so that most people wouldn't understand...)
They call 'JC' stealing one's account and doing bad things with it, especially in things they call "机房惨案", which means 'a bad plot in a computer room'
嗯嗯这知道的 跟体制内OIer接触够久了
In fact, even as a Chinese person, it's not easy for me to fully understand this sentence.
Dat's 'cuz you're a good student which is not polluted by your "fox friend dog mates" (I'm surely not good @ English, but I can't speak Chinese, or my contribution will never $$$ \gt 0$$$ qwq).
Well, I don't know what $$$1$$$ means.
Sometimes it's disgusting to connect sth. with another thing, like Chengdu and something not able to say. Chengdu is a nice city, though I'm not from Chengdu, it surely attracted me when I travelled there. CF (a school located in Chengdu) OIers are welcoming, and Jinjiang river is nice.
I'm from Chengdu. Chengdu is a good city.
Are you a CF OIer?
CF 是什么学校？
Chengdu Foreign Language School.
我们一般称之为 CW 吧
I'm not from Chengdu Foreign Language School.
I'm not from Chengdu Foreign Language School.
I've been to Chengdu and I like it very much.
Well, you're quite right. I should say sorry to everyone who saw my comment. It's not only for the reason that I ruins the eyes with my terrible comments, but also my politeness. It's an awful decision to play jokes about Chengdu and gays. Although we always connect them in talk as meme, it's improper to speak in this way on the Internet where competitors all over the world discuss problems. It's my mistake to behave so crazy on the website. I'm sorry. 要不我赔你点钱吧。
I'm sorry, too. 我也可以赔你点钱。
这不叫赔钱，这踏马叫嫖唱。
我喜欢你。
I love You.
My Codeforces rating is 1959, while yql0991666's is 2061.
Although I know that my total score of 313 in the Chinese NOI is low (Ranked in the lower half of the bronze medal tier), I still think I’m much stronger than a contestant who isn’t even eligible to participate in the provincial competitions (CSP-S and NOIP).
its completely ridiculous to see that such a terrible person getting such high rating without any cheating
momomomomo.
orzorzorzorz.
It's pretty annoying to see cheaters in contests,especially those who use AI.All they can do is to show off themselves even though they don't have the abililty to do so,and it's even worse that they will spread anxiety to others.
I think this should be stopped.
Spot on. It’s honestly exhausting. They're not just cheating; they're actively ruining the community vibe for everyone who actually tries.
its actually so disappointing that people do such things, even after cp is so fun
yql0991666 is obviously a cheater. Ban the cheater please.
1
I can't imagine how a CPer can arrive 1900 rating while he can't got CSP-J first prize.
Unless he wants to give hungreds of RMBs to the CCF.
I'm stronger than yql. I can get CSP-J first prize.
I'm weak, as I got 78 points in CSP-S last year.
But I'm still stronger than him/her, because I aked CSP-J last year and got 300pts in CSP-J 2024.
I have read it with great attention.
已严肃阅读是 read it carefully 或者 seriously 吧（
why people cheating in cf? You cant earn money or get something with your rating. I though cf its about lesson
it's for putting a link to your cf account on resumes so that they have a higher chance of getting hired
https://codeforces.me/blog/entry/155961 Lets check out what Mr. Cheater wants to tell us.
blog deleted :(
blog deleted :(
yql0991666 is definitely weaker than me.
Because I got 160 points in NOIP2025 , about 200 points in CSP-S , while yql0991666 only got 130 points in CSP-J.
emm.yes.?!
ma,ybe.!
I notices that the suspect made a 30pts progress in CSP-J through the gap of one year. I couldn't believe that within 0.8 years, he has become a CM and can get 250~300pts in CSP-S, cuz *2000 problems refer to cyan and blue problems in luogu. But if that's true, I ensure that I'd apologize and I'll look forward to this prospective OIER's AK IOI cordially./xyx
this guy has already got banned in Luogu LMAO he's obviously a cheater,CF should do something with taht
TestsNumT
TestsNumT
So what does TestsNumT mean qwq
The anti-AI variable name in the latest edu round on cf.
ok thx
TestsNumT
TestsNumT
TestsNumT
terrifying speed of progress! He will up to brown(a tag named"cheater" in luogu).
We shall cheat to the end!
we shall fight on the rating by cheating,
we shall change the style of AI's code for cheating
we shall defend our ranking by cheating, whatever the cost may be,
we shall fight on the CSP-J 2024 100pts,
we shall fight on the CSP-J 2025 130pts,
we shall never abandon cheating!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
and even if, which I do not for a moment believe, there are nothing we can do,
then our Qilong Yin comrade, undoutbedly will killed all problem in CSP2026 because he is a strong CM!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
by yql0991666
Great poem, great poem ah.
To be honest, it's pretty entertaining to watch dogs barking like crazy, don't you think?
He will waste me a whole afternoon. So funny!:>
It's a good way to pass the time:)
Great talent!
What an really, really, really, shameless, insane, crazy, unbelievable, disgusting, idoitic, incomprehensible cheating madman!!!!!!!!!!!!!!!!!!!!
Why are you listing the words that you know
Are you flexing your vocabulary or something
No---I was too exasperated at that moment, sorry. When one of my friends heard about this cheater, she was promptly like, "OMG he must've got on the newspaper headlines. But i suppose they didnt put his disgusting poem on (Of course not!), i bet some people will get a heart attack reading that."
Naming《Darkest Hour：Yql‘s Cheating Epic》
yup, his style is enough to say he is cheating
what's the meaning
don't remind me uwu
I've just upvoted the article owner BBB to apologise
.
Don't turn a comment to different comment.
Why? I'm trying to delete it
You should think why you can't delete comment after 3 minutes in Codeforces.
Link It's the third problem of CSP-J last year. That means, if you can solve it, you can probably get 300pts in CSP-J.
So, what will cheaters become in Codeforces?
(Idw to check the rule posts now)
MikeMirzayanov Vladosiya
why can he CM? I can get the first prize in CSP-J...
And I can get 310pts in CSP-J,so I am stronger than him.
%%%
Here are the four problems for CSP-J2025.
https://vjudge.net/problem/%E6%B4%9B%E8%B0%B7-P14357
https://vjudge.net/problem/%E6%B4%9B%E8%B0%B7-P14358
https://vjudge.net/problem/%E6%B4%9B%E8%B0%B7-P14359
https://vjudge.net/problem/%E6%B4%9B%E8%B0%B7-P14360
He only got 130 points, but his rating on Codeforces is 2061.
Yes. He couldn't solve all four problems, yet he got Master. That's obviously impossible.
If that is true,I should be M:)
So did anyone still remember SudoXue
SudoXue is not as strong as yql0991666 because yql0991666 AKed CNOI2026 in 40 minutes on Luogu, much faster than SudoXue.
At this point , I just do it for fun not for rating .... there is no proper way to identify all cheaters ig :')
since chatgpt and other LLM become stronger, I gradually lost interest in participating online contest.
Recent news: yql0991666 gets rank 54 (without unofficial) in Round 1117, having solved F1 while not solved D. This sign make him more suspicious of cheating.
upd: corrected the wrong problem id from "E1" to F1.
The evidence will be published tomorrow. I'm too tired and need to sleep now.
Actually not E1，it's even F1.
yql0991666, could you explain 387437964 387437988 how can you write 1.6KB code in 3 seconds?
Looking at the code for Problem E, what kind of person would write such a long definition on a single line (the fourth line)?
If you interpret this as a way to make the code more compact (by consolidating lines), then why are the assignment statements on lines 19 through 24 separated?
The only explanation is that the AI-generated code was partially modified.
He became Master yesterday... Please ban him codeforces, he'll get LGM soon if we doesn't stop him.
Cheating Master
Yes.
Finally yql0991666 reached 4000 and we will vote him a title "Legendary Cheating Master"
Look at his most recent performance... he solved problem B in less than a minute! Wow he's so great! I want to be just like him when I grow up! (bushi
WoW,God of Cheaters.
However, B is really simple, referring to Codeforces Round 1117 (Div. 2)
Actually 3 seconds.
maybe he is Nezha with 3 heads and 6 arms.
I am amazed that he has cheated again.
If he didn't cheat, I will be really amazed.
When others increase their ratings, they take the stairs, but yql0991666 takes the elevator—an elevator whose brakes have failed, going straight to the top. However, I believe that the elevator he is riding will eventually reach the apex, crashing forcefully into the top-level support beam and completely destroying the account. It now seems that day is not far off.
BitByBit123 pls can you make blog about suspicios Master azizs look how he participated at last contest as a proof (he got 5th place in official standings but he's a noname guy)
Hello! I am Yin Qilong from 2030! I will tell you 2 good news!
Yeah that's right.
sto Cute_Wazzy orz
There we go.He just became master.Good news huh?
Good News! yql0991666 have been banned!
The cheater got banned — talk about karma.
Congratulations! The cheater has been banned. I hope more cheaters will be found and ban the in future!
Congratulations on banning yql!
Good job banning, Codeforces did the right thing
yql will remain orange forever.
Justice has been served.
I, yql0991666, am finally banned! Congratulations to me!
https://codeforces.me/contests/with/Pirate-King (https://codeforces.me/contests/with/Pirate-King)
check this guy his name is rahul singh and he is cheating so smartly that no one can catch him. 6 months back he was an expert and all of sudden he can become international master. I know it is possible but he cant do that with very few problems solved.